I keep getting an infinite loop for my program but I cant seem to find whats causing it. I. thought it might be my switch statement but I can't find any syntax errors. Thank you.

#include

/* declare global var's, including total cycles,

total instruction count, and clock cycle rate */

float total_cycles;

int total_instructions;

float clock_rate;

/*********************************************************/

void enter_params()

{

/* declare local var's and initialize*/

total_cycles = 0.0;

total_instructions = 0;

int number_classes;

float cpi_i;

int instr_i;

/* prompt for # instruction classes & clock cycle rate of machine */

printf("Enter number of instruction classes");

scanf("%d", &number_classes);

printf("Enter the frequency of the machine (GHz)");

scanf("%f", &clock_rate);

/* for each instruction class, prompt for CPI of class and instruction count */

for(int i =1; i<= number_classes; i+=1){

printf("Enter the CPI of the class:%d ", i);

scanf("%f", &cpi_i);

printf("Enter instruction count of class %d (billion) ", i);

scanf("%d", &instr_i);

/* update values in appropriate glocal var's */

total_cycles += cpi_i * (float)(instr_i);

total_instructions += instr_i;

}

return;

}

/*********************************************************/

void calc_exectime()

{

/* declare local var's */

float exectime;

/* Calculate execution time and print result */

exectime = (total_cycles)/(clock_rate); //1000?

printf("The execution time of the sequence is: %f seconds", exectime);

return;

}

/*********************************************************/

void calc_mips()

{

/* declare local var's */

float MIPS;

float avg_cpi;

avg_cpi = total_cycles/(float)(total_instructions); //float?

/* Calculate MIPS and print result */

MIPS = clock_rate/(avg_cpi);

printf("The MIPS of the sequence is %.2f", MIPS);

return;

}

/*********************************************************/

void calc_avgcpi ()

{

/* declare local var's */

float avg_cpi;

avg_cpi = total_cycles/(float)(total_instructions);

/* Calculate average CPI and print result */

printf("The average of the sequence is: .%2f", avg_cpi);

return;

}

/*********************************************************/

int main()

{

int user_input;

int x =1;

/* until user chooses to quit, print menu,

select choice via switch statement and call appropriate function*/

while(x==1) {

printf("Measuring performance ");

printf("-------------");

printf("1. Enter Parameters ");

printf("2. Calculate Execution time of a sequence ");

printf("3. Calculate MIPS of a sequence ");

printf("4. Calculate average CPI of a sequence ");

printf("5. Quit program ");

printf("Enter choice");

scanf("%d", &user_input);

switch(user_input){

case 1: enter_params();

break;

case 2: calc_exectime();

break;

case 3: calc_mips();

break;

case 4: calc_avgcpi();

break;

case 5: return(0);

}

}

}